diff --git a/Project.toml b/Project.toml
index aa882cc..6993f89 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "EikonalSolvers"
 uuid = "0631ba50-6b23-11e9-3fc3-378508ba069a"
 authors = ["Andrea Zunino <6928707-anzun@users.noreply.gitlab.com>"]
-version = "0.15.2"
+version = "0.15.3"
 
 [deps]
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
diff --git a/src/EikSolv/eikutils.jl b/src/EikSolv/eikutils.jl
index 0ce9dd6..2e75a15 100644
--- a/src/EikSolv/eikutils.jl
+++ b/src/EikSolv/eikutils.jl
@@ -198,9 +198,9 @@ $(TYPEDSIGNATURES)
 
 Ray tracing utility. Given a traveltime grid and source and receiver positions, trace the rays.
 """
-function tracerays(grd::AbstractGridEik,ttime::Vector{Array{Float64}},
-                   coordsrc::Array{Float64,2},coordrec::Vector{Array{Float64,2}};
-                   steplen::Real=0.01)
+function tracerays(grd::AbstractGridEik,ttime::Vector{Array{T}},
+                   coordsrc::Array{T,2},coordrec::Vector{Array{T,2}};
+                   steplen::Real=0.01) where T
     
     nsrc = size(coordsrc,1)
     rays_srcs = Vector{Vector{Matrix{Float64}}}(undef,nsrc)
@@ -266,9 +266,9 @@ function tracerays_singlesrc(grd::AbstractGridEik,ttime::Array{Float64,N},
             
             #x,y = raypath[s,:]
             if Ndim == 2
-                gradT = gradient(itp,raypath[s,1],raypath[s,2])
+                gradT = Interpolations.gradient(itp,raypath[s,1],raypath[s,2])
             elseif Ndim == 3
-                gradT = gradient(itp,raypath[s,1],raypath[s,2],raypath[s,3])
+                gradT = Interpolations.gradient(itp,raypath[s,1],raypath[s,2],raypath[s,3])
             end